Tunnel liner segment



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TUNNEL LINER SEGMENT Original Filed Dec. 13, 1953 Patented Oct. 4,1938

TUNNEL LINER SEGMENT Charles B. Cushwa, Youngstown, Ohio, assignor to The Commercial Shearing & Stamping Company, Youngstown, Ohio, a corporation of Ohio Original application December 13, 1933, Serial No.

702,l88.- Divided and this application September 20, 1935, Serial No. 41,435

. 1 Claim.

My invention relates to linings for earth borings and, in particular, to fabricated linings having greater strength than such structures as known heretofore.

This is a division of my copending application SerialNo. 702,188, filed December 13, 1933, for Tunnel liners, now Patent No. 2,046,727, granted. July 7,1936.

Linings for earth borings, for example, tunnels, as usually constructed, include a plurality of rings disposed side by side and secured together, each ring being formed of an assembly of. segments. The loads sustained by such linings are not uniform as to distribution or direction and this fact makes it essential that the lining have great strength in order to withstand the loads which may be concentrated -at any particular area. While numerous types of segments for linings have previously been proposed, practically all of them with which I am familiar have been characterized by weak points. One of the points of greatest weakness in prior structures has been the fact that many of them relay on bent-up flanges to transmit circumferentially of the lining from one segment to itsneighbors, the radial force which may happen to befconcentrated thereon. It is obvious that a bent flange has a very low resistance to further bendingand is, therefore, a highly inefficient means for transmitting radial hrusts from one segment to adjacent segments.

I have invented a novel form of pressed steel segment from which tunnel linings may be asesembled. The segment of my invention is characterized, by great strength circumferentially of a completed lining ring for transmitting stresses applied radially of the completed lining. The

segments, furthermore, .are very rigid throughout their length. An embodiment of the invention is shown inthe accompanying drawing, together with a modification thereof, although the drawing is merely illustrative and does not represent the only forms in which the inventionmay be incorporated. In the drawing:

Figure l is a plan View of a segment according to my inventiony Figure 2 is a side elevation thereof;

Figure 3 is an end view;

Figure 4 is a sectional view along the line IVIV of Figure 1;

Figure 5 is a view similar to Figure 1 a modified form of the invention; v Figure 6 is a side elevation thereof;

Figure '7 is an end view; and

Figure 8 is a sectional view along the line VIII-VIII of Figure 5.

Referring in detail to the drawing, and for the present, to Figures 1 through 4 particularly, a

showing 7 segment ID is shaped by pressing, drawing, or otherwise, from a single plate; The side and end edges of the plate are bent downwardly to'form side flanges H and end flanges l2. A stiffening rib I3 is formed adjacent the center of the web portion !4 of the segment, i. e., the portion between the side and end flanges. The rib I3 is formed by slitting the web portion l4 adjacent the end flanges, as shown at 15, and'pressing inwardly the 'web material between the slits. The rib 13, 01 course, greatly increases the rigidity of the segment lengthwise, as compared'to a segment without the rib.

Figures 5 through 8 show another form of segment indicated at 20., The segment 20 is pressed from a single plate like the segment l0 but has separately formed end walls 2|. Theweb of the segment 20 is bent to form side flanges 22. The intermediate portions .of the web are doubled backon themselves toform ribs or plaits 23 extending longitudinally of the segment. The end walls 2| are attached to the ends of the segment by welding. It will be apparent that the lengthwise rigidity and strength of the segment of Figures 5 through 8 are even greater than those of the segment of Figures 1 through 4. Thenumber of ribs 23 may be varied to suit different conditions and the longitudinal strength and ri 'gidity of the segment will vary correspondingly.

A particular advantage of the construction shown in Figures 5 through 8 is that the ribs 23 abut against the end Walls 2| and therefore provide substantial support against inward bending of v the end walls which might otherwise result from the circumferential forces set up by stresses radial to the completed tunnel lining.

It will be apparent from the foregoing de .scription that my invention provides a number shown and described herein without departing from the spirit ofv the invention or the scope of the appended claim.

I claim:

A liner segment comprising a plate curved along one dimension, side walls extending in- Wardly of the curved edges of the plate, said plate having a plait forming a strengthening rib extending inwardly of the plate to substanitally the depth of said side walls and end walls welded to the ends of the side Walls and of the plait.

' CHARLES B. CUSI-IWA. 

